一种油罐底板实时监漏的新方法

针对当前被广泛使用的通过罐内油位变化和感官查库对油罐底板进行实时监漏的方法存在的弊端,提出了油罐底板实时监漏的新方法,即油罐基础内钻孔油气体积分数监漏法.介绍了油罐底板实时监漏方法的探漏原理:在油罐基础上按每9m(弧长)钻取一个直达砂垫层的探漏孔,使用高灵敏度的油气含量检测仪探测到油气,可判断罐底是否发生渗漏.以实例阐述了操作步骤和现场应用情况,证明了其有效性,详述了其技术要求.基于现场实验数据,提出了汽油油罐的判漏标准,可为今后油库的扩容和改造提供借鉴.     

大直径人工挖孔扩底灌注桩实际应用及效益比较

本文通过对大孔径人工挖孔扩底灌注桩基础与一般钻孔灌注桩基础受力及经济比较,在地质条件合适的情况下,推荐采用大孔径人工挖孔扩底灌注桩基础。     

底部框架砖房抗震设计中应注意的问题

作者根据哈尔滨实际情况,论述了底部框架砖房防震设计中应注意的问题。对指导哈尔滨城市建设,具有一定的实用性。     

441千瓦双船底拖网网口高度与网口周长的关系

本文报道了１９８６￣１９９２年期间对４４１ｋＷ渔船使用的１顶度拖网网口高度的海上实测结果。结果表明：网口高度是网口拉直周长的５．５￣７．３％。两者的关系可用经验公式表示为：Ｈ＝０．２６０９Ｌ＾０．７３４４。     

棉花黄萎病抗性鉴定新方法——无底塑钵菌液浇根法

通过一系列的试验 ,笔者发展了一种快速鉴定棉花品种抗黄萎病性能的新方法—无底塑钵菌液浇根法 ,此法比传统的纸钵撕底醺根法更简便 ,发病较轻 ,能准确客观地反映品种的抗性     

厩肥对粉煤灰微量元素释放规律影响的研究

该文对粉煤灰在降雨淋洗条件下微量元素的释放规律进行了室内模拟试验。试验处理分别为粉煤灰、粉煤灰+石灰、粉煤灰+石灰+厩肥及其混合物的堆肥腐熟4种情况。实验结果显示淋出液中B、Sr、Ba和Li的最大浓度大于1 mg/L，而其它元素均小于此值。石灰的应用增大了淋出液中B和Ba的浓度而降低了Li、Mo和Cr的浓度；厩肥的应用及其堆肥腐熟处理增大了B、Mo、Zn、V以及Cu、Ni、Cd、As、Mn、Ti、Co、Sn和Se的浓度，而降低了Sr、Ba、Li和Cr的浓度。除V外，淋出液中所有微量元素的浓度随淋出液体积的增加而减小。Cr、Zn以及Cd、Cu和As可能是粉煤灰对环境产生潜在危害的主要元素。     

螺纹铣削工艺的选择

总结了在数控加工中心上进行螺纹铣削的一些注意事项,其中包括螺纹铣削刀具的选用及测定、螺纹铣削底径的确定、铣削方式的选择及精度控制等。     

Composition,distribution and sources of polycyclic aromatic hydrocarbons in sediments of the western harbour of alexandria,egypt

Aim and Background  Little data are available on the levels of polycyclic aromatic hydrocarbons (PAHs) in the sediments of the Mediterranean Sea Coast of Egypt in general and the Alexandria coastal zone in particular. It was therefore deemed necessary to set up a monitoring programme to determine the current concentrations of PAHs in bottom sediments, and to identify any area where high concentrations of these potential hazardous contaminants were present in the Western Harbour of Alexandria. Methods  The composition, distribution and the source of PAHs in surficial sediments of the harbour were investigated. To document the spatial PAH input, surficial sediment samples from 23 locations throughout the harbour were analysed. as]Results and Discussion The total PAH load determined in the surficial sediment samples ranged from 8 to 131150 ng g¹ dry wt, generally with most of the samples having total concentrations of PAHs greater than 5000 ng g¹ dry weight. The highest concentration of total PAHs was recorded in sediments of the inner harbour. Ratio values of specific compounds such as phenanthrene to anthracene, fluoranthrene to pyrene, methyl-phen-anthrene to phenanthrene, methyl-dibenzothiophenes to dibenzothiophenes, alkylated to non-alkylated and high molecular weight to low molecular weight PAH, were calculated to evaluate the possible source of PAH contamination in the harbour sediments. Conclusions  Two main sources of PAH in the study area have been found: pyrolytic and petrogenic. Interferences of rather petrogenic and pyrolytic PAH contaminations were noticed for most samples. The dominant sources of PAH appear to be the combustion processes through run-off, industrial and sewage discharges, and atmospheric input. The concentrations of PAHs were generally above levels expected to cause adverse biological effects. Recommendations and outlook  Information from this study and any other relevant studies should be useful in designing future strategies for environmental protection and management of the harbour.     

光诱鱿鱼浮拖网渔具渔法试验

首先对诱鱼光场进行计算，并分析其对光诱鱿鱼浮拖网作业的影响，据此合理配置了灯光强度及其布局，探讨了一套较有效的诱导渔方法。根据鱿鱼的趋光习性及浮拖网的特点，设计了适应在较深渔场作业的光诱浮拖网渔具，并成功地试验了光诱鱿鱼浮拖网柔性网板；取得了良好的社会生态效益和经济效益。     

智利竹鱼拖网最适网囊网目尺寸探讨

根据拖网网囊网目尺寸与鱼体生物学存在关系 ,对智利竹鱼的优势叉长组成、形体特征、初次性腺成熟时的叉长等进行了分析。通过现场测试得出 2 0 0 0年智利竹鱼的优势叉长为 2 5 0～ 30 0mm ;体高、体宽和体周与叉长存在线性关系 ,分别为 2a =0 .185 8L - 3 .5 2 19,2b =0 .1339L - 4.2 99,c =0 .480 3L - 3 .4794。并对智利竹鱼拖网网囊网目尺寸进行了分析与计算 ,认为智利竹鱼拖网网囊的最适网目内径为 115～ 12 0mm。